The National Institute on Drug Abuse (NIDA), Medications Development Division (MDD) has established a Cocaine Treatment Discovery Program (CTDP) to accelerate the identification of potential medications for the medical management of cocaine dependence. This program involves testing compounds through a decision-based screening scheme designed to identify potential treatment agents which will either antagonize the effects of cocaine or substitute for cocaine. The purpose of this contract is to determine the affinity of up to 600 test compounds at biogenic amine transporter (dopamine, serotonin, and norepinephrine) binding sites. In addition, up to 500 of these compounds will be assessed for their ability to inhibit the reuptake of biogenic amines and up to 200 of them will be evaluated for their ability to facilitate an "amphetamine-like" release of biogenic amines. Compounds will, in general, be submitted by NIDA to the contractor "blind" with a coded identification number and information about the compound such as their physical properties and solubility. CTDP data generated from this contract on proprietary compounds will be maintained in confidence by NIDA for three (3) years from the date of reporting of each test result to the compound submitter. After three (3) years, NIDA will disclose this information into the public domain through its MDD structure-activity database. Compound submitters are free to disclose CTDP data generated on their compounds prior to the three (3) year period of non-disclosure. The contractor will meet annually with NIDA and consultants with expertise in in vitro biogenic amine transporter as says to review the quality of the contract data and discuss new state-of-the-art technologies and methodologies for potential incorporation into the contract.